Testing Vermiculite for Asbestos: Why the USGS’s New Method Could Be Critical for Public Health

In a breakthrough study, the U.S. Geological Survey (USGS) found a way to test for trace levels of asbestos in vermiculite insulation on-site, which marks a promising development in public health.

Approximately 1 million homes in the United States contain vermiculite attic insulation that puts families at risk of exposure to asbestos, the only known cause of mesothelioma and other aggressive, fatal diseases.

The tool USGS developed tests specifically for amphibole asbestos, 1 of 2 groups of asbestos types. It’s a good start, but families should be mindful that there is no safe level of exposure to any form of the deadly mineral – and there are many other places in the home where asbestos may be lurking.

What Is Vermiculite Asbestos Insulation?

Vermiculite is a naturally-occurring mineral silver-gold to gray-brown in color and shiny in its natural state. When heated to around 1,000 °C, vermiculite flakes expand and form pockets of air, making the material seemingly ideal for use as insulation.

Vermiculite itself does not pose a health problem. However, that and other building materials were historically reinforced with asbestos for addexd heat- and fire-resistance. And when inhaled, asbestos fibers pose a deadly risk.

One major source of commercially produced vermiculite insulation was Libby, Montana, home to the now-infamous Libby mine. The mine, now permanently closed, is part of the Environmental Protection Agency’s Superfund program. That said, many of the homes that the Libby mine once supplied with vermiculite insulation are still in urgent need of asbestos testing. USGS’s goal is to streamline a process that leaves too much room for danger.

USGS’s Simple, Time-Saving Solution

The goal of the agency’s study was to experiment with what’s called near-infrared reflectance spectroscopy (an analytical technique commonly used to study soil and plant matter). Using this method, they hypothesized, we could detect the source of the vermiculite and therefore whether it’s likely to contain asbestos.

Researchers studied 52 vermiculite samples from around the world, including from Libby, Montana. All 24 insulation samples from Libby were found to contain amphibole asbestos; from the other locations, “relatively little.”

As hoped, USGS successfully used spectroscopy to trace the samples back to their sources. The team proposed that asbestos contractors use portable spectrometers when surveying homes to confirm whether insulation came from Libby.

“Based on medical studies, there is general agreement that all Libby vermiculite insulation is potentially hazardous,” said Gregg Swayze, a Denver-based USGS scientist. “This study demonstrates that spectrally determining the source of attic vermiculite as Libby, provides enough information to make a [prompt] remediation decision.”

Protecting Yourself and Your Family from Vermiculite Insulation

Traditionally, asbestos professionals have had to submit samples of the vermiculite insulation they find to an off-site lab, where it would undergo time-consuming analyses. But the insulation left behind in this process would still pose occupants a substantial risk. All it takes is a single, microscopic asbestos fiber to sign a death sentence when inhaled.

This is crucial but relatively new public knowledge. Firefighters, construction workers, the military, other workers, and their families were exposed to asbestos for the greater part of the 20th century before research exposed risks asbestos companies tried to keep hidden. Had these companies not put so many workers at risk, the 3,200 new mesothelioma diagnoses that arise each year would be substantially lower.

Until asbestos is banned in the U.S., there is a limit to what can be done to stop exposure universally. But that little can be enough to save an individual’s life. Keeping your home safe means making small efforts not to disturb your insulation (which releases asbestos fibers into the air). If you suspect it is vermiculite,

  • Avoid using your attic for storage. If possible, avoid entering it at all.
  • Hire a licensed and trained asbestos professional when making renovations.
  • Seal any cracks or holes in the ceiling near your attic to keep the insulation localized.
  • Seal all windows and door frames in your home, as insulation can fall inside the walls.
  • Never attempt to remove the insulation yourself.
  • Look out for signs of asbestos elsewhere in the home.

Learn more about protecting your family from asbestos on the EPA’s website.

Sokolove Law Team

Contributing Authors

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Last modified: May 17, 2019