Kevin Maillefer / Unsplash
By Lynne Peeples
Editor’s note: This story is part of a nine-month investigation of drinking water contamination across the U.S. The series is supported by funding from the Park Foundation and Water Foundation. Read the launch story, “Thirsting for Solutions,” here.
In late September 2020, officials in Wrangell, Alaska, warned residents who were elderly, pregnant or had health problems to avoid drinking the city’s tap water — unless they could filter it on their own.
More than 3,000 miles (4,800 kilometers) away, the people of Scituate, Massachusetts, received a letter that same month cautioning about the same group of contaminants in their drinking water.
At issue wasn’t any of the well-known and widely feared water infiltrators such as E. coli or per- and polyfluoroalkyl substances (PFAS). The culprit chemicals tainting taps from Cocoa, Florida, to the Finger Lakes of New York to a correctional facility in Only, Tennessee, are, in fact, less recognized yet more ubiquitous: disinfection by-products.
“Take a glass of water. You may or may not have pesticides, pharmaceuticals, PFAS and lead in it. Usually not,” says Susan Richardson, a professor of biochemistry at the University of South Carolina in Columbia. “But there’s always something that is in your drinking water, and that’s disinfection by-products.”
Aptly named, the chemicals form in water when disinfectants that are widely used to kill pathogens in municipal drinking water facilities react with organic compounds. These compounds may be present in the water as a result of natural processes such as the decay of leaves and animal matter, as well as human activities that may release solvents, pharmaceuticals, pesticides and industrial chemicals. Exposure to disinfection by-products through drinking, bathing or swimming has been linked to potential increased risks of low birthweight babies, birth defects, miscarriages and cancer.
“Disinfection is hugely important. We’ve got to kill those pathogens,” says Richardson. “We had millions of people dying from waterborne illnesses before we started disinfecting water in the 1800s.”
Cholera and typhoid fever were once deadly and pervasive threats. Still today, when concentrations of disinfectants fall too low, drinking water can become a breeding ground for dangerous pathogens such as Legionella, E. coli, even cholera.
“It’s a trade-off between inactivating pathogens that are going to make people sick today versus the long-term, low-level risk of chemicals in the water,” says Christy Remucal, an associate professor of civil and environmental engineering at the University of Wisconsin–Madison.
Striking a balance may be even more challenging today as waters become increasingly compromised due to population growth, wastewater intrusion, energy exploration, climate change — and now the Covid-19 pandemic, according to Richardson.
During the pandemic, many places have increased use of chlorine for disinfection in indoor and outdoor settings and during wastewater treatment, resulting in the potential for higher levels of disinfection by-products. Authors of a study published in October warn that this “upsurge and overuse of chlorine-based disinfectants” may pose a threat to human health “by impacting water quality.”
Concentrations of harmful chemicals have also likely increased in buildings left vacant during Covid-19 shutdowns. The longer that water sits in pipes, explains Richardson, the longer it has to react with disinfectants and form more by-products.
Still, Gregory Korshin, a professor of civil and environmental engineering at the University of Washington in Seattle, encourages perspective on the issue of disinfection by-products. The answer, he and others say, is not to stop disinfecting water, nor is it for everyone to buy bottled water.
“There is a dark side of disinfection,” adds Korshin. “But this doesn’t compromise the notion that drinking water in the U.S. is safe.”
Unintended Consequences
Chemists first discovered disinfection by-products in treated drinking water in the 1970s. The trihalomethanes they found, they determined, had resulted from the reaction of chlorine with natural organic matter. Since then, scientists have identified more than 700 additional disinfection by-products. “And those only represent a portion. We still don’t know half of them,” says Richardson, whose lab has identified hundreds of disinfection by-products.
Identification of disinfection by-products is incredibly difficult, she explains, because these chemicals are not simply flowing down a river from an industrial site or running off a farm. “They didn’t exist before,” she adds. “It’s a complete unknown — there’s no preconceived idea of what these chemicals look like.”
Another research team recently discovered more previously unidentified disinfection by-products. As they described in a January 2020 study, potentially carcinogenic chemicals are formed through the interaction of chlorine and not only organic matter in the environment but also manmade materials that include phenols such as bisphenol A (BPA) and other plasticizers, as well as sunscreen agents and antimicrobials.
“These phenol compounds are incredibly widespread because of their properties,” says Carsten Prasse, a coauthor on the study and an assistant professor of environmental health and environmental engineering at Johns Hopkins University. He highlights their use in both plastic pipes and plastic bottles, which frequently carry drinking water.
What’s Regulated and What’s Not?
The U.S. Environmental Protection Agency (EPA) currently regulates 11 disinfection by-products — including a handful of trihalomethanes (THM) and haloacetic acids (HAA). While these represent only a small fraction of all disinfection by-products, EPA aims to use their presence to indicate the presence of other disinfection by-products. “The general idea is if you control THMs and HAAs, you implicitly or by default control everything else as well,” says Korshin.
EPA also requires drinking water facilities to use techniques to reduce the concentration of organic materials before applying disinfectants, and regulates the quantity of disinfectants that systems use. These rules ultimately can help control levels of disinfection by-products in drinking water.
Click the image for an interactive version of this chart on the Environmental Working Group website.
Still, some scientists and advocates argue that current regulations do not go far enough to protect the public. Many question whether the government is regulating the right disinfection by-products, and if water systems are doing enough to reduce disinfection by-products. EPA is now seeking public input as it considers potential revisions to regulations, including the possibility of regulating additional by-products. The agency held a two-day public meeting in October 2020 and plans to hold additional public meetings throughout 2021.
When EPA set regulations on disinfection by-products between the 1970s and early 2000s, the agency, as well as the scientific community, was primarily focused on by-products of reactions between organics and chlorine — historically the most common drinking water disinfectant. But the science has become increasingly clear that these chlorinated chemicals represent a fraction of the by-product problem.
For example, bromide or iodide can get caught up in the reaction, too. This is common where seawater penetrates a drinking water source. By itself, bromide is innocuous, says Korshin. “But it is extremely [reactive] with organics,” he says. “As bromide levels increase with normal treatment, then concentrations of brominated disinfection by-products will increase quite rapidly.”
Emerging data indicate that brominated and iodinated by-products are potentially more harmful than the regulated by-products.
Almost half of the U.S. population lives within 50 miles of either the Atlantic or Pacific coasts, where saltwater intrusion can be a problem for drinking water supplies. “In the U.S., the rule of thumb is the closer to the sea, the more bromide you have,” says Korshin, noting there are also places where bromide naturally leaches out from the soil. Still, some coastal areas tend to be spared. For example, the city of Seattle’s water comes from the mountains, never making contact with seawater and tending to pick up minimal organic matter.
Hazardous disinfection by-products can also be an issue with desalination for drinking water. “As desalination practices become more economical, then the issue of controlling bromide becomes quite important,” adds Korshin.
Other Hot Spots
Coastal areas represent just one type of hot spot for disinfection by-products. Agricultural regions tend to send organic matter — such as fertilizer and animal waste — into waterways. Areas with warmer climates generally have higher levels of natural organic matter. And nearly any urban area can be prone to stormwater runoff or combined sewer overflows, which can contain rainwater as well as untreated human waste, industrial wastewater, hazardous materials and organic debris. These events are especially common along the East Coast, notes Sydney Evans, a science analyst with the nonprofit Environmental Working Group (EWG, a collaborator on this reporting project).
The only drinking water sources that might be altogether free of disinfection by-products, suggests Richardson, are private wells that are not treated with disinfectants. She used to drink water from her own well. “It was always cold, coming from great depth through clay and granite,” she says. “It was fabulous.”
Today, Richardson gets her water from a city system that uses chloramine.
Toxic Treadmill
Most community water systems in the U.S. use chlorine for disinfection in their treatment plant. Because disinfectants are needed to prevent bacteria growth as the water travels to the homes at the ends of the distribution lines, sometimes a second round of disinfection is also added in the pipes.
Here, systems usually opt for either chlorine or chloramine. “Chloramination is more long-lasting and does not form as many disinfection by-products through the system,” says Steve Via, director of federal relations at the American Water Works Association. “Some studies show that chloramination may be more protective against organisms that inhabit biofilms such as Legionella.”
If a drinking water facility fails to meet EPA regulations for disinfection by-products, one relatively easy and cheap modification is to add ammonia to the existing treatment, turning chlorine to chloramine. Many large community water systems in the U.S. now use chloramine. By doing so, according to Richardson, they have dropped levels of regulated disinfection by-products by up to as much as 90%.
However, there is one major drawback to this shift: the creation of potentially more harmful by-products. “It might push down on regulated disinfection by-products, but then other things pop up that are even more toxic,” says Richardson, whose research team discovered previously unknown disinfection by-products in chloraminated drinking water. One of those finds, iodoacetic acid, is the most DNA-damaging disinfection by-product known to date.
Prasse underscored the concern: “From a regulatory perspective, we could say we’re fine. But it’s a false sense of security.”
Rather than continuing on the toxic treadmill of replacing one potentially toxic chemical for another, a more effective solution may be to focus upstream in the treatment process — such as keeping organics out of the system in the first place. “That requires engineers, chemists, toxicologists and regulators to come together and figure something out,” says Prasse.
Alternative Approaches
When he moved to the U.S. from Germany, Prasse says he immediately noticed the bad taste of the water. “You can taste the chlorine here. That’s not the case in Germany,” he says.
In his home country, water systems use chlorine — if at all — at lower concentrations and at the very end of treatment. In the Netherlands, chlorine isn’t used at all as the risks are considered to outweigh the benefits, says Prasse. He notes the challenge in making a convincing connection between exposure to low concentrations of disinfection by-products and health effects, such as cancer, that can occur decades later. In contrast, exposure to a pathogen can make someone sick very quickly.
But many countries in Europe have not waited for proof and have taken a precautionary approach to reduce potential risk. The emphasis there is on alternative approaches for primary disinfection such as ozone or ultraviolet light. Reverse osmosis is among the “high-end” options, used to remove organic and inorganics from the water. While expensive, says Prasse, the method of forcing water through a semipermeable membrane is growing in popularity for systems that want to reuse wastewater for drinking water purposes.
Remucal notes that some treatment technologies may be good at removing a particular type of contaminant while being ineffective at removing another. “We need to think about the whole soup when we think about treatment,” she says. What’s more, Remucal explains, the mixture of contaminants may impact the body differently than any one chemical on its own.
Richardson’s preferred treatment method is filtering the water with granulated activated carbon, followed by a low dose of chlorine.
Granulated activated carbon is essentially the same stuff that’s in a household filter. (EWG recommends that consumers use a countertop carbon filter to reduce levels of disinfection by-products.) While such a filter “would remove disinfection by-products after they’re formed, in the plant they remove precursors before they form by-products,” explains Richardson. She coauthored a 2019 paper that concluded the treatment method is effective in reducing a wide range of regulated and unregulated disinfection by-products.
Greater Cincinnati Water Works installed a granulated activated carbon system in 1992, and is still one of relatively few full-scale plants that uses the technology. Courtesy of Greater Cincinnati Water Works.
Despite the technology and its benefits being known for decades, relatively few full-scale plants use granulated active carbon. They often cite its high cost, Richardson says. “They say that, but the city of Cincinnati [Ohio] has not gone bankrupt using it,” she says. “So, I’m not buying that argument anymore.”
Greater Cincinnati Water Works installed a granulated activated carbon system in 1992. On a video call in December, Jeff Swertfeger, the superintendent of Greater Cincinnati Water Works, poured grains of what looks like black sand out of a glass tube and into his hand. It was actually crushed coal that has been baked in a furnace. Under a microscope, each grain looks like a sponge, said Swertfeger. When water passes over the carbon grains, he explained, open tunnels and pores provide extensive surface area to absorb contaminants.
While the granulated activated carbon initially was installed to address chemical spills and other industrial contamination concerns in the Ohio River, Cincinnati’s main drinking water source, Swertfeger notes that the substance has turned out to “remove a lot of other stuff, too,” including PFAS and disinfection by-product precursors.
“We use about one-third the amount of chlorine as we did before. It smells and tastes a lot better,” he says. “The use of granulated activated carbon has resulted in lower disinfection by-products across the board.”
Richardson is optimistic about being able to reduce risks from disinfection by-products in the future. “If we’re smart, we can still kill those pathogens and lower our chemical disinfection by-product exposure at the same time,” she says.
Reposted with permission from Ensia.
Refugees from Afghanistan, Somalia, Sudan, Ethiopia, Yaman, Sri Lanka and Bangladesh live in roadside tents while awaiting work permits in Jakarta, Indonesia on June 19, 2018. Anton Raharjo / Anadolu Agency / Getty Images
By Ambika Chawla
When the rains never arrived in the East African nation of Somalia in 2016, nor in 2017, hundreds of thousands of rural residents were forced to abandon their lands and livelihoods due to one of the most severe droughts in decades. Then, in 2019, from September to December, heavy rains led to severe flooding there, displacing hundreds of thousands of people from their homes in rural areas and towns in the districts of Belet Weyne, Baardheere and Berdale.
These climate migrants traversed barren and dusty landscapes, or traveled through torrential rains, in search of food and shelter. Many ended up in refugee camps in urban areas such as Badbaado, a sea of makeshift tents on the outskirts of Mogadishu that is now home to tens of thousands of internally displaced persons.
The challenges they face are profound, says Ben Mbaura, national emergency response and disaster risk reduction coordinator at the International Organization for Migration (IOM), including inter clan conflict, poor sanitation, limited education and insufficient access to food. On top of that, many “do not have the necessary skills to match labor market needs, which also results in high levels of unemployment and exclusion,” Mbaura notes.
The response to internal displacement like this has long been to provide emergency or short-term assistance. In recent years, however, with so many internally displaced persons living in protracted displacement, humanitarian organizations have increasingly recognized the need to empower them to move toward greater self-reliance. As a result, in 2016 the U.N. and the government of Somalia created the Durable Solutions Initiative (DSI) as a way to introduce long-term solutions for internally displaced persons in Somalia. The DSI gives these people a voice in decision-making processes that shape their future — and offers a model for other cities that are, or soon will be, in similar circumstances.
Fragile Cities
Every year, millions of people around the world are forced to abandon their lands, livelihoods and communities due to the effects of climate change. And the rate of climate-induced migration is increasing — with most taking place in the form of rural-urban migration within countries.
According to a recent World Bank report, “internal climate migrants” could number more than 143 million by 2050, mainly in sub-Saharan Africa, Latin America and South Asia. If the past is any indication, most will be forced from their homes by extreme weather events. Others will move from rural areas to cities due to slow-onset climate-related events, such as desertification.
Humanitarian experts predict that the current trajectory of climate change will displace millions of people in the Global South. Source: Kanta et al. 2018. Groundswell: Preparing for Internal Climate Migration. Washington, D.C.: The World Bank.
Pablo Escribano, a specialist on migration and climate change in Latin America for the IOM, says this migration will create “urban hot spots” where displaced persons converge in search of shelter, food and jobs.
Climate migrants who arrive in cities are likely to move to informal settlements, and many of these hot spots will occur in rapidly expanding cities in low- and middle-income countries with weak governance and limited capacities to provide social services and infrastructure.
“In Asia, recent estimates of the increase in sea-level rise have strong implications for cities like Jakarta, Bangkok and Dhaka,” Escribano says.
In Latin America, he says, Rio de Janeiro, Lima, La Paz and Mexico City will experience migration pressure from sea-level rise, melting glaciers and other climate-change effects. “Fast-growing cities in Africa, such as Lagos, Luanda and Kinshasa are also considered to be city hot spots,” he adds.
Urban development expert Robert Muggah has dubbed these urban settings as “fragile cities.” As the co-founder and research and innovation director of the think tank Igarapé Institute in Brazil, Muggah developed 11 indicators that determine urban fragility, including crime, inequality, lack of access to services and climate change threats.
Ani Dasgupta, global director for the Ross Center for Sustainable Cities at the World Resources Institute (WRI), says fast-growing cities face multiple threats that increase the vulnerability of new arrivals.
“As cities expand, many municipal governments are overburdened. They are not able to keep up with increasing demand for basic services, like housing, jobs, electricity and transport,” he says. “The climate crisis is an additional challenge on top of this. Flooding, heat waves, water shortages and more powerful storms tend to affect new migrants and already vulnerable populations most severely.”
Move Toward Self-Reliance
The goal of the DSI is to strengthen the ability of government at all levels — local, state and federal — to help internally displaced persons integrate into society. It has mobilized funding from donors such as the World Bank, U.N. agencies and the Peacebuilding Fund (the U.N.’s financial resource for supporting peace in areas experiencing or at risk of conflict) to support initiatives that allow internally displaced persons to present their ideas for community infrastructure projects along with strategies to become self-reliant.
Teresa Del Ministro, the DSI coordinator for Somalia, says the DSI is a response to a growing global awareness of the limitations of traditional humanitarian approaches to deal effectively with internally displaced persons. “With that trend increasing worldwide, it appeared that multi-stakeholder partnerships are needed at all levels,” she says.
The DSI is considered particularly innovative because it lets internally displaced persons articulate the kinds of solutions they need to move toward self-reliance.
“A participatory, locally owned approach is one of the programming principles for the DSI,” says Isabelle Peter, the DSI’s coordination officer.
One example is the Midnimo I project supported by the Peacebuilding Fund with the IOM and UN-Habitat as partners.
With support from Midnimo I (“midnomo” means “unity” in Somali), climate migrants and other displaced persons in southern and central Somalia met with representatives of their host communities, along with city and national government officials, to develop creative solutions to the many challenges they face. Among other things, the initiative sought to help communities define and drive their own recovery — most prominently through community action plans (CAPs), documents that lay out local priorities for community-driven recovery.
As part of Midnimo I, the IOM trained Somali government representatives to engage displaced persons in visioning exercises to help them articulate their short-term needs and present ideas on strategies to move toward greater self-reliance.
Ali Hussein camp on the outskirts of Burao, Somaliland, is home to numerous families displaced by conflict and drought. Photo courtesy of Oxfam East Africa from Wikimedia, licensed under CC BY 2.0
Midnimo I was implemented in the cities of Kismayo and Baidoa, home to more than 450,000 internally displaced persons.
“Together they would come up with priorities for infrastructure investments or other types of investments. If a project didn’t have funding for these priorities, the government would convene other actors and ask for their support,” says Del Ministro.
According to an evaluation report by the IOM, the Midnimo I project created short-term employment opportunities, led to the construction of community infrastructure projects and contributed to the establishment of a land commission and to improved relations between authorities and displaced communities. Nearly 350,000 people directly benefited from the Midnimo I project as a result of constructing or upgrading community-prioritized schools, hospitals, water sources, police stations, prisons, airports and more, according to the IOM’s Mbaura.
The DSI in Ethiopia
The DSI also has been implemented in Ethiopia, where a drought that began in 2015 left millions dependent upon emergency food aid. The government of Ethiopia, with support from U.N. agencies, governments, donor agencies and non-governmental organizations, launched its own DSI in December 2019. As in Somalia, the focus is on long-term self-reliance.
“The scale of the displacement surprised many in the international community, and there was recognition that collectively we needed to support Ethiopia,” says Hélène Harroff Atrafi, the DSI coordinator in the U.N. Resident Coordinator’s Office. “In doing so, we looked at international good practices, including in neighboring Somalia.”
At this point, the governance structure for the DSI is being established with the government of Ethiopia in the lead. “We have agreed on the vision forward, we have brought together all of the partners who want to work together. Now the operational rollout must begin,” says Atrafi.
In the Somali region, one of 10 regions in of Ethiopia, the DSI is now at the stage of detailing the options that internally displaced families have: urban and rural relocation, return to the location of origin, and potential integration in the settlements where the displaced individuals currently reside.
According to the World Bank report “Groundswell: Preparing for Internal Climate Migration,” the number of climate migrants in Ethiopia could close to triple by 2050, with Addis Ababa set to become an urban hot spot for climate induced migration. Smaller cities, such as Jigjiga and Deri Dawa, are also expected to receive increasing waves of climate migrants.
In February 2020, Ethiopia ratified the African Union Convention for the Protection and Assistance of Internally Displaced Persons (IDPs) in Africa, a legally binding instrument for protecting internally displaced persons in Africa. There is hope this will bring greater awareness about the need to support innovative, participatory initiatives for internally displaced persons there.
Looking Forward
Around the world, fragile city governments can partner with international humanitarian organizations, NGOs, research institutions, the private sector, U.N. agencies and other city governments to strengthen their capacities to tackle challenges at the intersection of urbanization, climate and migration.
For the Internal Displacement Monitoring Center (IDMC), a think tank based in Geneva, multi-stakeholder partnerships play a crucial role in gathering information about internally displaced persons.
“We start with the people affected — internally displaced persons and host communities — and from there, we build up the agenda, collaborating with national governments, U.N. agencies, NGOs, academia and research centers,” says Pablo Ferrández, a research associate with the IDMC.
Andrew Fuys, senior director for global migration at the nonprofit Church World Service, says that one of the priorities for research is to identify how the risks climate migrants face are similar to, or differ from, those of other internally displaced persons in cities so that organizations can provide the appropriate services for climate migrants.
Del Ministro and Peter say the long-term success of the DSI in Somalia will depend on overcoming a number of challenges. Organizers will need to ensure there are sufficient resources for community-led initiatives, overcome obstacles to coordination, and strengthen the capacities of city governments.
“Stronger capacities are needed in human resources in city planning,” Peter says. “There is a need to have financial resources available. Developing the skills and knowledge of people who are equipped to deal with challenges in cities is needed.”
Oana Baloi, a program management consultant for UN-Habitat in Ethiopia, emphasizes the need for city governments to gain greater access to climate-related finance opportunities.
“Despite the well-designed programmatic approach to implement durable solutions, unless a climate change adaptation strategy is delivered at the regional and local levels, we may expect further climate change–induced displacement,” says Baloi. “Accessing climate financing for large scale interventions to ensure adaptation and displacement prevention remains a challenge.”
Ferrández says there is also a need for decentralization so towns and smaller cities receive adequate resources to support internally displaced persons.
“Bringing efforts to achieve durable solutions from the national to municipal level also means intervening beyond areas such as Baidoa, Kismayo and Mogadishu, where the international presence is strong, to secondary cities and rural areas,” he says.
With the coming years, climate-induced migration to “urban hot spots” is likely to intensify. As it does, collaborations across sectors can help fragile city governments deliver a more effective humanitarian response in times of crisis while empowering internally displaced persons to play a central role in efforts to fully integrate into society. The hope is that, when climate migrants are given a voice in decision-making processes in fragile cities they can devise solutions that will lead to a more secure future not only for themselves and the cities in which they live, but for future generations.
Reposted with permission from Ensia.
More than 200 million Americans may be drinking PFAS-contaminated water, research suggests. vitapix / Getty Images
By Lynne Peeples
Editor’s note: This story is part of a nine-month investigation of drinking water contamination across the U.S. The series is supported by funding from the Park Foundation and Water Foundation. Read the launch story, “Thirsting for Solutions,” here.
Tom Kennedy learned about the long-term contamination of his family’s drinking water about two months after he was told that his breast cancer had metastasized to his brain and was terminal.
The troubles tainting his tap: per- and polyfluoroalkyl substances (PFAS), a broad category of chemicals invented in the mid-1900s to add desirable properties such as stain-proofing and anti-sticking to shoes, cookware and other everyday objects. Manufacturers in Fayetteville, North Carolina had been discharging them into the Cape Fear River — a regional drinking water source — for decades.
“I was furious,” says Kennedy, who lives in nearby Wilmington. “I made the connection pretty quickly that PFAS likely contributed to my condition. Although it’s nothing that I can prove.”
The double whammy of bad news came more than three years ago. Kennedy, who has outlived his prognosis, is now an active advocate for stiffer regulation of PFAS.
“PFAS is everywhere,” he says. “It’s really hard to get any change.”
Indeed, various forms of PFAS are still used in a spectrum of industrial and consumer products — from nonstick frying pans and stain-resistant carpets to food wrappers and firefighting foam — and have become ubiquitous. The compounds enter the environment anywhere they are made, spilled, discharged or used. Rain can flush them into surface sources of drinking water such as lakes, or PFAS may gradually migrate through the soil to reach the groundwater — another key source of public water systems and private wells.
For the same reasons the chemicals are prized by manufacturers — they resist heat, oil and water — PFAS also persist in the soil, the water and our bodies.
More than 200 million Americans may be drinking PFAS-contaminated water, research suggests. As studies continue to link exposures to a lengthening list of potential health consequences — including links to Covid-19 susceptibility — scientists and advocates are calling for urgent action from both regulators and industry to curtail PFAS use and to take steps to ensure the compounds already in the environment stay out of drinking water.
Thousands of Chemicals
PFAS dates back to the 1930s and 1940s, when Dupont and Manhattan Project scientists each accidentally discovered the compounds. The Minnesota Mining and Manufacturing Company, now 3M, soon began manufacturing PFAS as a key ingredient in Scotchgard and other non-stick, waterproof and stain-resistant products.
Thousands of different PFAS chemicals emerged over the following decades, including the two most-studied versions: PFOS and PFOA. Oral-B began using PFAS in dental floss. Gore-Tex used it to make waterproof fabrics. Hush Puppies used it waterproof leather for shoes. And DuPont, along with its spin-off company Chemours, used the compounds to make its popular Teflon coatings.
Science suggests links between PFAS exposure and a range of health consequences, including possible increased risks of cancer, thyroid disease, high cholesterol, liver damage, kidney disease, low birth-weight babies, immune suppression, ulcerative colitis and pregnancy-induced hypertension.
“PFAS really seem to interact with the full range of biological functions in our body,” says David Andrews, a senior scientist with the nonprofit Environmental Working Group (EWG, a collaborator on this reporting project). “Even at the levels that the average person has in this country, these chemicals are likely having an impact.”
The U.S. Centers for Disease Control and Prevention (CDC) has even issued a warning that exposure to high levels of PFAS might raise the risk of infection with Covid-19 and noted evidence from human and animal studies that PFAS could lower vaccine efficacy. A PFAS known as PFBA is raising particular concern with respect to the global pandemic. Philippe Grandjean, a professor of environmental medicine at the University of Southern Denmark and at the Harvard T.H. Chan School of Public Health in Cambridge, Massachusetts, and colleagues recently found a positive correlation between severity of Covid-19 symptoms and the presence of PFBA in individuals’ blood, according to their non-peer-reviewed preprint paper published in October.
“There is a whole range of potential adverse effects. To me, the interference with the immune system is the most important,” Grandjean says. “According to our data, the immune system is affected at the lowest exposure levels.”
Water Woes
Once PFAS gets into the environment, the compounds are likely to stick around a long time because they are not easily broken down by sunlight or other natural processes.
Legacy and ongoing PFAS contamination is present across the U.S., especially at or near sites associated with fire training, industry, landfills and wastewater treatment. Near Parkersburg, West Virginia, PFAS seeped into drinking water supplies from a Dupont plant. In Decatur, Alabama, a 3M manufacturing facility is suspected of discharging PFAS, polluting residents’ drinking water. In Hyannis, Massachusetts, firefighting foam from a firefighter training academy is the likely source of well-water contamination, according to the state. Use of PFAS-containing materials such as firefighting foam at hundreds of military sites around the country, including one on Whidbey Island in Washington State, has also contaminated many drinking water supplies.
“It works great for fires. It’s just that it’s toxic,” says Donald (Matt) Reeves, an associate professor of hydrogeology at Western Michigan University in Kalamazoo who studies how PFAS moves around, and sticks around, in the environment.
It can be a near-endless loop, Reeves explains. Industry might discharge the compounds into a waste stream that ends up at a wastewater treatment plant. If that facility is not outfitted with filters that can trap PFAS, the chemicals may go directly into a drinking water source. Or a wastewater treatment facility might produce PFAS-laced sludge that is applied to land or put into a landfill. Either way, PFAS could leach out and find its way back in a wastewater treatment plant, repeating the cycle. The compounds can be released into the air as well, resulting in some cases in PFAS getting deposited on land where it can seep back into drinking water supplies.
His research in Michigan, he says, echoes a broader trend across the U.S.: “The more you test, the more you find.”
In fact, a study by scientists from EWG, published in October 2020, used state testing data to estimate that more than 200 million Americans could have PFAS in their drinking water at concentrations of 1 part per trillion (ppt) or higher. That is the recommended safe limit, according to some scientists and health advocates, and is equivalent to one drop in 500,000 barrels of water.
“This really highlights the extent that these contaminants are in the drinking water across the country,” says EWG’s Andrews, who co-authored the paper. “And, in some ways, it’s not a huge surprise. It’s nearly impossible to escape contamination of drinking water.” He references research from the CDC that found the chemicals in the blood of 98% of Americans surveyed.
Inconsistent Regulation
U.S. chemical makers have voluntarily phased out their use and emission of PFOS and PFOA, and industry efforts are underway to reduce ongoing contamination and clean up past contamination — even if the companies do not always agree with scientists on the associated health risks.
“The weight of scientific evidence from decades of research does not show that PFOS or PFOA causes harm in people at current or historical levels,” states Sean Lynch, a spokesperson for 3M. Still, he notes that his company has invested more than US0 million globally to clean up the compounds: “As our scientific and technological capabilities advance, we will continue to invest in cutting-edge cleanup and control technology and work with communities to identify where this technology can make a difference.”
Thom Sueta, a company spokesperson for Chemours, notes similar efforts to address historic and current emissions and discharges. The company’s Fayetteville plant has dumped large quantities of the PFAS compound GenX, contaminating the drinking water used by Kennedy and some 250,000 of his neighbors.
“We continue to decrease PFAS loading to the Cape Fear River and began operation this fall of a capture and treatment system of a significant groundwater source at the site,” Sueta stated in an email.
A big part of the challenge is that PFAS is considered an emerging contaminant and is, therefore, not regulated by the U.S. Environmental Protection Agency (EPA). But most of the ongoing PFOS and PFOA contamination appear to come from previous uses cycling back into the environment and into people, notes Andrews.
A big part of the challenge is that PFAS is considered an emerging contaminant and is, therefore, not regulated by the U.S. Environmental Protection Agency (EPA). In 2016, the EPA set a non-binding health advisory limit of 70 ppt for PFOA and PFOS in drinking water. The agency proposed developing federal regulations for the contaminants in February 2020 and is currently reviewing comments with plans to issue a final decision this winter.
Several U.S. states have set drinking water limits for PFAS, including California, Minnesota and New York. Michigan’s regulations, which cover seven different PFAS compounds, are some of the most stringent. Western Michigan University’s Reeves says that the 2014 lead contamination crisis in Flint elevated the state’s focus on safe drinking water.
Still, the inconsistency across the country has created confusion. “The regulation of PFAS remains varied. States are all having different ideas, and that’s not necessarily a good thing,” says David Sedlak, a professor of civil and environmental engineering at the University of California, Berkeley. “People are uncertain what to do.”
The Interstate Technology and Regulatory Council, or ITRC, a coalition of states that promotes the use of novel technologies and processes for environmental remediation, is working to pull together evidence-based recommendations for PFAS regulation in the absence of federal action.
University of Southern Denmark and Harvard professor Grandjean suggests a safe level of PFAS in drinking water is probably about 1 ppt or below. The European Union’s latest risk assessment, which Grandjean says corresponds to a recommended limit of about 2 ppt for four common PFAS compounds, is “probably close,” he says. “It’s not a precautionary limit, but it’s certainly a lot closer than EPA’s.”
GenX, introduced in 2009 by DuPont to replace PFOA, is among a newer generation of short-chain PFAS designed to have fewer carbon molecules than the original long-chain PFAS. These were initially believed to be less toxic and more quickly excreted from the body. But some evidence is proving otherwise: Studies suggest that these relatives may pose many of the same risks as their predecessors.
“The family of PFAS chemicals being used in commerce is a lot broader than the small set of compounds that the EPA is considering regulating,” says Sedlak. “Up until now, the focus of discussion related to regulation has centered around PFOS and PFOA with some discussion of GenX. But the deeper we dig, the more we see lots and lots of PFAS out there.”
Andrews notes that the ongoing pattern of replacing one toxic chemical with another is a problem that the federal government urgently needs to fix. “This entire family of chemicals shares many of the same characteristics,” he says.
“When these chemicals stop being produced, especially in significant volumes across the country, the levels go down,” Andrews says, referring to a corresponding drop in PFOS and PFOA concentrations in Americans’ blood after the phaseout of the compounds. “But it raises that concern of what’s coming next? Or what are we really being exposed to that we’re not testing for?”
Andrews and his co-author Olga Naidenko, also a scientist with EWG, further urge governments to consider one relatively low-hanging fruit: non-essential uses of PFAS. “Even if somebody would make an argument that, for serious fires, we need to use the best foam, I think we can all agree that there’s no reason to spray PFAS just to train,” says Naidenko. “You can spray water.”
Environmental health advocates express hope that 2021 will bring greater progress on PFAS regulation. President-elect Joe Biden has pledged to set enforceable limits for PFAS in drinking water and to designate PFAS as a hazardous substance — which would accelerate the cleanup of contaminated sites under the EPA’s Superfund program.
Breaking the Chain
Meanwhile, the million-dollar (or realistically much, much more) question is: How do we get PFAS out of drinking water? The bond between carbon and fluorine atoms is one of the strongest in nature. As a result, PFAS degrades extremely slowly in nature. “People have called them ‘forever chemicals’ for good reason,” says Sedlak. “These carbon-fluorine bonds want to stay put.”
Because PFAS resists degradation, filtration is the primary strategy for removing it from drinking water. Granulated activated carbon filters can absorb PFAS and other contaminants, although they must be replaced when all of the available surface area becomes occupied by chemicals. The filters also tend to work less well for short-chain compared to long-chain PFAS. Another removal method is the use of ion exchange resins, which can attract and hold negatively charged contaminants such as PFAS. Perhaps the most effective technology to date is reverse osmosis. This approach can filter out a wide range PFAS. At the same time, it carries a high price tag, notes Heather Stapleton, a professor of environmental science and policy at Duke University in Durham, North Carolina.
Stapleton has researched the various filters and finds that all of them can work well. She installed an at-home filter after discovering PFAS in her own drinking water. But that cost can be a significant barrier for many people, she notes, making it an “environmental justice issue.”
The diversity of PFAS compounds also poses a challenge. Community water systems may spend significant resources to install systems for water treatment only to find that while the method might work well at removing one set of PFAS, it can fail to filter another set, says Naidenko.
Scientists are investigating further chemical and biological treatment methods. Sedlak is among researchers looking into ways to treat PFAS while it is still in the ground, such as via in situ oxidation coupled with microbes to break down chemicals.
“What we know for sure is we were exposed. What we don’t know is what sort of lasting health impact that has on us as a community” – Emily DonovanJoel Ducoste, a professor of civil, construction and environmental engineering at NC State University in Raleigh, North Carolina, laments that currently employed treatment processes still fall short of removing PFAS and providing safe drinking water to Americans. “This has been problematic in our state and is becoming a national problem,” he says.
More definitive science surrounding PFAS — optimal treatment methods, truly safe alternatives and potential health effects — can’t come soon enough for those dealing daily with legacy PFAS contamination in Wilmington.
“What we know for sure is we were exposed. What we don’t know is what sort of lasting health impact that has on us as a community,” says Emily Donovan, co-founder of Clean Cape Fear, a grassroots group advocating for clean water in the region. Part of their effort, she says, is seeking better medical monitoring of people exposed to PFAS.
Due to the long latency between exposure and disease — often decades — it is difficult to link any PFAS with specific cancers. Kennedy notes no history of breast cancer in his family and no genetic predisposition to the disease. “Those factors made me believe even more that it was PFAS responsible for this,” he says.
“It seems like that’s not the right way to test chemical safety — the big underlying concern here — to expose the population widely. And yet, that seems to be what we’re doing now,” says Andrews.
Reposted with permission from Ensia.
