PCBs in Schools

The Basics About PCBs

A Brief History of PCBs

PCBs were manufactured in the US from 1929-1979. The EPA’s toxic substances and control act (TSCA) banned production of PCBs in 1979. PCBs may be present in products and materials produced before the 1979 PCB ban. Products that may contain PCBs include:

Fluorescent light ballasts
Caulking
Floor finish
Oil-based paint
Thermal insulation material e.g. fiberglass, felt, foam, & cork
Transformers & capacitors
Electrical equipment including voltage regulators, switches, re-closers, bushings, & electromagnets
Oil used in motors & hydraulic systems
Old electrical devices or appliances containing PCB capacitor
Cable insulation
Adhesives & tapes
Plastics
Carbonless copy paper

The Health Effects of PCBs

PCBs are carcinogenic to humans and animals. PCBs can affect the immune system, reproductive system, nervous system and endocrine system. PCBs are a ‘forever chemical’ and do not easily break down once in the environment. They can accumulate in food crops, animals and humans.

The worst case for human exposure to PCBs is the school room: Dr Keri Hornbuckle is one of the leading researchers in PCBs and has studied PCBs in the environment for more than 30 years. Recently she has shown that PCBs in school air pose a health hazard to children and people working in schools and that many schools harbor surprisingly high levels of PCBs. According to Dr Hornbuckle, “a high level of misunderstanding about PCBs persists, even among scientists. These misconceptions are not benign but in fact result in long-term harm to our population. These misconceptions support inaction to protect the public and contribute to an ongoing and highly unjust assault on health.” In 2022, Dr Hornbuckle published Common Misconceptions about PCBs Obscure the Crisis of Children’s Exposure in School in the journal Environmental Science and Technology, in which she and her collaborators highlight the following:

The worst case for human exposure is a school room, not living near a PCB superfund site.
Children are among the most vulnerable to PCB toxicity.
Even though manufacturing of PCBs was banned, they still remain in materials such as PCB light ballasts, adhesives under floor tile, to masonry sealants, to window caulking, and to the glaze used between glass blocks frequently found in school rooms.
PCB concentrations in buildings built during the PCB era have increased levels of airborne PCBs. Until materials with PCBs are removed, they will continue to degas PCBs into the room air.
Exposure to PCBs through inhalation can be higher than that from ingestion through diet.

More than 50,000 schools were built or remodeled during the PCB era of 1950–1980, but it is unknown how many of those schools contain PCBs. 

Vermont’s Program Tackling PCBs in Schools

Vermont’s Burlington High School and New Legislation

In August 2020, Vermont’s Burlington High School was found to have PCBs in surrounding soil at levels exceeding EPA regulations of 50 parts per million (ppm). The PCBs were attributed to building materials and indoor air tests found concentrations of PCBs of up to 6,300 nanograms per cubic meter (ng/m³). School classes went remote and relocated to a nearby vacant Macy’s building. In 2023 the high school was demolished and new construction is expected to be completed in 2026 and costing over $200M.

In 2021 Vermont legislation was passed (Act 74 / H.439) requiring that all schools constructed or renovated before 1980 must conduct indoor air testing for PCBs. Vermont is the only state to have made testing for PCBs in schools a requirement. The Vermont Department of Environmental Conservation (VTDEC) was provided $4.5M to perform indoor air testing for airborne PCBs, and to develop a program to test Vermont schools for PCBs.

How Schools Are Tested

Schools requiring testing were identified and scheduled for indoor air testing. An indicator was developed to show a school when PCB abatement is necessary. Building on the EPA’s exposure levels for evaluating PCBs in indoor school air, the School Action Level (SAL) indicator was developed, A school’s SAL is a threshold of the amount of PCBs in an air sample, measured in nanograms per cubic meter (ng/m³). It’s value is based on the youngest grade of students at the school: 30 ng/m³ for pre-K, 60 ng/m³ for kindergarten to 6th grade and 100 ng/m³ for 7th grade to adult. A second indicator called the Immediate Action Level (IAL) was also defined and set to three times the SAL. Rooms with air PCB concentrations exceeding the IAL are regarded as hazardous and are not to be used. Both SALs and IALs are based on 235 days of exposure for 9.75 hours per day.

At schools, environmental consultants are used to identify materials potentially containing PCBs in rooms, and to perform indoor air sampling. School rooms are grouped by similar potential PCB material sources. Grouping rooms together in this way allows the extrapolation of data from tested rooms to untested rooms. During school sampling events, air samples are taken in a third of the rooms in each group after any obvious PCB sources are removed. If the PCB concentration in an air sample exceeds the school’s SAL, then material samples are taken from rooms in the group and tested to identify the sources of PCBs. The school is provided with a temporary room occupancy plan to use for reducing student and staff exposure to PCBs in the rooms with the highest PCB levels. The school works to abate the PCBs with guidance from the State, and is reimbursed through education grants. Further indoor air testing is done to monitor the effect of the work. More information is available at the VTDEC’s PCBs in Schools website.

Explore School Testing Status and Schedule

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There are 438 schools in Vermont with 328 (or 75%) requiring testing for PCBs. As of November 14, 2024, 146 (or 45%) schools have been tested between June 30, 2022 and November 14, 2024.

Schools were first surveyed to identify which were built or renovated before 1980 and require testing. They were then assigned a prioritization score between 0 and 10, with 10 being the highest priority. The prioritization score is based on criteria such as the date the school was built or renovated, and the percentage of students with free or reduced lunch. More information is available at the VTDEC’s PCBs in Schools website, together with the latest testing schedule.

Explore Schools Needing Testing, the Testing Schedule and Testing Sampling Events

Use the School Testing Status view to see which schools require testing and when. Use the School Prioritization & Testing Timeline view to explore when schools were scheduled for testing, and when sampling events occurred.

Explore Airborne PCB Changes Over Time

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How Average Airborne PCB Concentrations Changed Each Month

Average concentrations of airborne PCBs in school rooms fluctuated each month, possibly due to changes in temperature or other environmental factors. This pattern is visible when grouping PCB air sample results by month. Hover over the chart for more information about each month.

How Airborne PCB Concentrations Have Changed at Retested Schools

The interactive chart below shows how airborne PCB concentrations have changed between sampling events at schools that have been tested multiple times. The basic statistics are calculated using all air samples at each sampling event. Select a retested school to explore. Hover over points on the lines for more information.

How Airborne PCB Concentrations Have Changed at Mitigated Schools

When airborne PCB concentrations in a room exceeds the School Action Level (SAL), PCB materials are abated across the campus group that contained the room. Recall that a campus group is a collection of rooms grouped together by similar materials that may be emitting PCBs. Abatement can take the form of mitigation and/or remediation actions. Mitigation refers to non-permanent actions such as using fans, opening windows and installing carbon filters.  Remediation refers to permanent actions, such as the removal or encapsulation of the materials containing PCBs. The sampling data contains information that can be used to determine if mitigation work was performed in each sampled room in a campus group (note – remediation information is not currently available).

The table below shows schools that had campus groups containing rooms in which PCB mitigation work was done. The columns show how airborne PCB concentrations changed for those campus groups. The metrics (average, median, etc) are calculated using air sample results from the rooms that had the mitigation work done and were then retested. Click on a school to explore a chart showing how the chosen metric changed between sampling events for the mitigated campus groups. Choose a metric to explore using the metric menu below the table. Hover over the information in the table and chart for more details.

Note: The results are not adjusted to take into account the monthly variation pattern shown earlier. With more annual data over time, it will be possible to measure the progress of mitigation work by comparing results from the same month year-over-year.

Estimated Financial Costs of PCB Testing and Abatement

During the 2024 ASTSWMO Superfund and Brownfields Symposium, the VTDEC presented ‘PCB Testing in Vermont Schools‘, in which costs per school were outlined as follows:

Average cost to identify and inventory potential PCB materials : $7,000 – $16,000
Average cost to perform indoor air sampling and analysis for airborne PCBs : $11,000 – $30,000
Estimated cost of materials sampling and analysis : $10,000 – $300,000
Estimated cost of PCB abatement work : $50,000 – $18M

Using these cost ranges, the total estimated costs for all 328 schools that require testing can be estimated to be as much as $2 billion, using the following assumptions:

1. All 328 schools require inventorying of building materials that may contain PCBs
2. The 32% (i.e. 104 out of 328) proportion of schools found so far to have airborne PCB concentrations at or above the School Action Level (SAL) applies to all 328 schools that need testing.
3. 32% (i.e. 104 out of 328) of schools require materials sampling/analysis and PCB abatement work due to SAL exceedances.

National Scale Potential

According to the National Center for Educational Statistics (NCES) digest state dashboard, there are around 130,000 schools in the US. Applying the results found in Vermont, 97,500 schools (or 75%) may require testing for PCBs and 31,200 schools (or 32%) could require PCB abatement. Obviously these are large assumptions and more investigation and testing would be in the interest of school children and teachers nationally.