# Widespread Emissions of Polychlorinated Biphenyls from Building Materials in Vermont Schools

## TL;DR

This study found that old building materials in Vermont schools are still releasing harmful PCBs into the air, posing cancer risks to students and staff.

## Contribution

The study identifies specific building materials emitting high levels of PCBs and quantifies cancer risks in school environments.

## Key findings

- PCB emissions from materials like sealant and fireproof coatings exceeded 30,000 ng/m²/day in multiple schools.
- Airborne PCB concentrations varied widely, with some rooms reaching 5700 ng/m³.
- Estimated cancer risks for school staff range from 1.3 × 10⁻⁸ to 1.7 × 10⁻⁴ depending on exposure levels.

## Abstract

In collaboration with Vermont state and school officials,
we conducted
a research study to measure emissions of polychlorinated biphenyls
(PCBs) from room surfaces in Vermont schools. Our study, the largest
of its kind, investigated the sources of airborne PCBs in indoor school
environments. Using simultaneous deployment of air samplers and emission
samplers, we measured airborne PCBs in 16 schools and 98 school rooms
constructed prior to 1980. There was a wide range in PCB air concentrations
(1.7–5700 ng m–3, n = 159)
and surface emissions (33–830,000 ng m–2 d–1, n = 182) across different schools
as well as between rooms in the same school. We found that emissions
of PCB congeners from walls, floors, ceiling and wall expansion joint
caulking, and spray insulation explain the airborne PCB congener concentrations
in many rooms. Our emission samplers identified three distinct types
of building materials with emissions exceeding 30,000 ng m–2 d–1 including expansion joint sealant (up to 480,000
ng m–2 d–1), glass block windows
(up to 30,000 ng m–2 d–1), and
fireproof coating on steel columns (up to 830,000 ng m–2 d–1). Consequently, school staff have an estimated
excess lifetime cancer risk from both dioxin-like and nondioxin-like
PCBs that ranges from 1.3 × 10–8 to 1.7 ×
10–4 for central tendency exposure, and 2.8 ×
10–8 to 3.8 × 10–4 for reasonable
maximum exposure (State of Vermont’s target cancer risk = 1
× 10–6). Although production has been banned
for decades, our study illustrates that PCBs continue to pose an exposure
risk to occupants due to their long history of use in building materials.
Our findings underscore the risks associated with the historic presence
of PCB-containing building materials, offering critical insights for
community efforts aimed at reducing exposure among children and school
staff in thousands of schools across the country.