Most people by now know about lead and asbestos: toxic substances found in old buildings that can cause great harm to people’s health and the natural environment.
But health and environmental experts say chemicals known as PCBs—polychlorinated biphnenyls—represent an emerging front in the ongoing battle for detoxifying the nation’s infrastructure, including its aging schools. These chemicals are less widely known but pose substantial risks to people who spend time in school buildings and a challenge for the people managing the money that fuels students’ learning.
Here’s what school leaders, and the people they serve, need to know about PCBs.
What are PCBs?
Polychlorinated biphenyls are man-made chemical compounds that typically appear as oily solids or liquids, and aren’t very water-soluble. Some estimates say 1 million tons of them were produced worldwide, a majority of them in the United States.
When were they used?
Polychlorinated biphenyls were first created in the late 19th century, but they emerged widely in construction materials in the late 1920s and early 1930s. They were in circulation through the 1970s and their manufacture was banned in the U.S. more than 40 years ago.
Buildings from the 1980s aren’t out of the woods when it comes to PCB contamination, either, said Bernie Mizula, the director of environmental health and safety for the International Union of Painters and Allied Trades: “When you phase something out of use, it’s not like every contractor or business owner says, ‘I’m going to search my factory or shop for all these lead-based paints and throw them right out.’”
Even in places where, for instance, light fixtures that may have contained PCBs were replaced, contractors might have missed a few on their way through the building—"the janitor’s closet, the boiler room, the athletic closet,” said Elinor Fanning, a toxicologist for the Washington state health department.
What were they used for?
Road crews used them in sticky liquid form to keep dust from flying up. They can be found in television sets and radios, microscopes, and electrical equipment, where they served as insulators and lubricants.
They’re nonflammable, they don’t smell, and they last a long time. In construction, they were used primarily to keep caulk and insulation from drying out, helping building materials last longer. That was particularly desirable for public buildings, like schools and government offices, which are intended to last a long time and weather constant wear and tear.
“I’ve heard anecdotes from construction workers where they were talking about PCBs being the secret sauce they’d mix into glues to make it last longer and easier to work with,” said Rachel Marek, an assistant research scientist who studies PCBs at the University of Iowa. “Construction workers actually really liked it until we all realized it was toxic.”
What happens to people who are exposed to harmful levels of PCBs?
A wide range of things. Once they enter the body, they’re not likely to leave. Health effects associated with PCB exposure may involve cardiovascular, gastrointestinal, immune, musculoskeletal, and neurological systems.
- Cancer, including non-Hodgkin’s lymphoma
- Skin lesions or rashes
- Abdominal pain
- Reproductive disorders
- Higher susceptibility to pneumonia and viral infections
- Impaired memory, vision, and attention span
- High blood pressure
- Neurological and development delays for young children and children exposed in utero
- Weight gain or weight loss in children born to women who are exposed
Unlike other toxic chemicals like asbestos, PCBs can affect people’s health even if they’re not disturbed, thanks to their ability to spread from walls and surfaces to the air.
When was their manufacture banned in the U.S.?
In 1979, the U.S. Environmental Protection Agency added PCBs to the list of substances banned from being manufactured, but data showing the harmful effects of PCBs existed well before the EPA took that step. To date, PCBs are only one of nine entries on that list. They’re also among roughly a dozen chemicals banned globally, according to the Stockholm Treaty on Persistent Organic Pollutants enacted in 2001.
Subsequently, the agency published regulations outlawing construction materials that contain more than 50 parts per million of PCBs. (Bob Herrick, a senior lecturer of public health at Harvard University, says 1 part per million is equivalent to a drop of water in a 10-gallon tank, or 1 inch in 16 miles.)
To what extent have they lingered? Where?
Though the EPA prohibited the manufacture of PCBs and requires remediation, it doesn’t require schools or other institutions to proactively seek the chemicals out in places where they were already used.
A 2016 study by Herrick estimated between 13,000 and 26,000 school buildings in the United States contain building caulk laced with PCBs. If removing PCBs from each one required $2 million, that could mean a nationwide remediation cost of $25 billion to $50 billion, according to a 2016 report from the office of U.S. Sen. Ed Markey, D-Mass. Herrick has contributed testimony on behalf of plaintiffs in legal cases against Monsanto, the company that manufactured PCBs.
Some researchers believe the number could be even higher, especially when factoring in schools with multiple buildings and schools that don’t have PCBs in caulk but do have them in other places, like light fixtures or tiles.
Of the 1,700 school buildings listed in Massachusetts’ online inventory alone, for instance, slightly more than half were built between 1950 and 1979, the critical period for PCB proliferation.
School buildings aren’t the only places where PCBs have lingered. Construction crews found them in the Cannon House Office Building on Capitol Hill in 2019 while preparing for renovation.
Meanwhile, states including Illinois, Maryland, and New Jersey in the last year have sued Monsanto, which was the primary manufacturer of PCBs, over contamination in waterways. A class action covering 2,500 cities and towns resulted in a $650 million court settlement in 2020. Washington state, the first in the country to sue Monsanto over PCB contamination, won $95 million in a 2016 settlement, and Ohio won $80 million in a 2022 settlement.
Why haven’t schools gotten rid of PCBs?
Remediating PCBs can be a logistical nightmare. Sometimes, it means shutting down and razing an entire school campus. At minimum, it often means cordoning off portions of a school building. And determining precisely where PCBs in the air are coming from is a challenge even before the remediation process begins.
That’s not to mention the cost. The Burlington district in Vermont spent millions of dollars relocating its high school operations to a temporary facility and will spend roughly another $200 million to build a new PCB-free building in the old one’s place. Even for schools that don’t need to be fully replaced, PCB mitigation can cost hundreds of thousands of dollars.
Who is most likely to be harmed by PCBs?
Underresourced districts—in many cases, disproportionately populated by low-income students and students of color—are more likely to have fallen behind on building renovations or lack the staffing to proactively track environmental hazards. High-poverty districts tend to have far fewer funds to spend on school facilities than in tax-rich districts.
Environmental-justice advocates point out that communities of color have long been disproportionately exposed to toxic substances. In the 1980s, the state of North Carolina’s plan to dump 30,000 gallons of PCB-laden soil near a rural, predominantly Black community prompted six weeks of protests and led to over 500 arrests.
Why is it so difficult to understand the effects PCBs have on the body?
It’s impossible to create a control group because, thanks to decades of pollution of waterways and the air, “everybody has PCBs in their body,” said David Carpenter, a public-health physician and PCB expert at the University of Albany. “What you do in any human study is compare people with lower exposure to people with higher exposure.” Carpenter has contributed testimony on behalf of plaintiffs in legal cases against Monsanto.
But PCBs are rarely the only chemical found in the body. DDT and other pesticides tend to have similar effects on humans, so researchers sometimes struggle to sort out which chemicals are causing which health problems. Studies of cells and animals tend to be more reliable.
For a long time, researchers focused on humans’ intake of PCBs via the food they ate—particularly seafood from contaminated waterways. But a 2012 study by researchers at the University of Iowa found that people who lived near a contaminated waterway in East Chicago didn’t have higher PCB levels in their blood than people who lived in Comus Junction, Iowa. That study helped shift researchers’ focus to the buildings where people spend their time—including schools.
How do you test for them?
Experienced PCB-testing contractors typically start with a physical inspection of caulk, paint, light ballasts, floor and ceiling, gym-floor varnish, and even transformers on the site. Then they sample pieces of all those items in bulk and the air as well.
After the materials that contain PCBs are removed, crews conduct another inspection to make sure that the materials around the affected area don’t still have lingering PCBs.
Individuals can also get their blood tested by commercial labs that determine PCB levels. The labs are less common than the labs that process routine drug tests, but general practitioners may be able to help find them.
What counts as a harmful level?
The EPA doesn’t require schools to test for PCBs, but it does provide guidance for schools that do test. Here are the maximum levels of PCBs they say are acceptable without remediation:
Some states have stricter action levels than the EPA; Vermont, for instance, requires schools to take action on PCB levels of 30 nanograms per cubic meter in pre-K facilities, 60 for kindergarten to 6th grade, and 100 for 7th grade to adult.
EPA regulations require disposal in a toxic-waste dump, like the ones listed on its website, of any materials that contain more than 50 ppm of PCBs. They don’t, however, require institutions like schools to test whether PCB levels meet that threshold, though they do offer online guidance.
Where has remediation happened?
Malibu High School in Southern California has undergone substantial renovations to manage its PCB problems after parents sued in 2016 and petitioned a judge to require the district to take action.
Clark Elementary School in Hartford, Conn., shut down permanently in 2015, and its students were relocated elsewhere after high levels of PCBs were discovered.
Burlington High School in Burlington, Vt., has met the same fate, though plans are in motion to replace its campus with a new facility.
What is the federal government doing about this?
Not much. Sen. Markey in 2016 published a report on the problems with PCBs in schools and promised legislation to fund remediation would follow. Five years later, a bill finally emerged but has languished so far in Congress.
Markey, joined by U.S. Reps. Jamaal Bowman, D-N.Y., and Andy Levin, D-Mich., this February called for the EPA to include funding for PCB remediation in schools in its annual budget. The agency didn’t respond to that request.
The Obama administration was working on tightening regulations for PCBs in schools and other buildings, but the Trump administration reversed those efforts, and the Biden administration doesn’t appear to have picked them up.
What are states doing about this?
Vermont passed a law in June 2021 requiring the state’s environmental conservation department to test all pre-1980 school buildings for PCBs. Lawmakers also included $32 million in one-time funds to remediate PCB concerns that arise.
Washington state hasn’t gone so far as to require testing statewide. But after a Seattle Times and ProPublica investigation this January exposed long-standing PCB problems in the state’s Monroe district, lawmakers the following month approved $1.5 million for schools to replace old light fixtures—regardless of whether they test positive for high levels of PCBs. The state also commissioned a study from researchers at the University of Washington to determine the appropriate standards for remediation and the costs of doing that work statewide.
At least 18 state websites offer PCB guidance geared toward schools, and seven more have a general page about PCBs, according to an Education Week analysis. But that leaves roughly half of U.S. states—including Alabama, Indiana, Georgia, Kansas, Pennsylvania, and Texas—that don’t appear to offer schools easily accessible guidance on how to deal with this toxic threat.
How does America’s school finance system affect the challenges districts will face with PCBs?
More than 10 states don’t provide any funds for school districts to spend on improving facilities or building new ones. And districts in nearly every state have to rely in part on local tax revenue to fix their infrastructure.
As a result, the list of deferred maintenance projects is sprawling, and the costs are explosive. U.S. schools collectively spend an estimated $85 billion less per year than would be needed to fully modernize buildings nationwide, according to a 2021 analysis by advocacy groups including the 21st Century School Fund Inc., the International WELL Building Institute, and the National Council on School Facilities.
What are the debates over policy approaches to tackling PCBs?
Without testing mandates, schools typically discover PCB issues when community members start falling sick or right before a big construction project. If schools were able to keep up with their maintenance needs, they might be finding PCBs more easily or they might have the budgetary space to proactively tackle urgent health concerns that will be expensive to remediate.
A nationwide effort to address PCBs in schools should start with schools that serve the youngest children, said Keri Hornbuckle, a professor of civil and environmental engineering who runs a PCB research group at the University of Iowa.
“Setting one level at which it would be safe or not seems unlikely to me to ever occur,” said Hornbuckle. “What we should be thinking about is, how can we limit exposure to these chemicals?”
Hornbuckle has contributed testimony on behalf of plaintiffs in legal cases against Monsanto.
How PCBs Disrupt School Districts: A Vermont high school shut down and sent students and staff to a former Macy’s after high levels of PCBs were discovered. Here’s what unfolded.
Rural Schools Should Expect Confusion: Administrators at a rural Vermont school were flummoxed on how to move forward—and how to pay—after the state told them they’d need to remediate PCBs.
A PCB Primer: What you need to know about polychlorinated biphenyls, where they’re found, the threats they pose, and what can be done about them.
A Visual Guide to PCBs: How do these chemicals move from one part of a school building to another? How does exposure affect humans? An animated guide.
What Schools Can Do Now: Schools are often reluctant to test for PCBs because they’re afraid of what they might find. These proactive steps can make a difference.
The Human Toll of PCBs: A former teacher in Washington state shares the illnesses that ended her full-time teaching career and the lawsuit she pursued as a result.
Maya Riser-Kositsky, Librarian and Data Specialist contributed to this article.