New study challenges assumption of asbestos' ability to move in soil

A new study led by Scripps Institution of Oceanography at the University of California San Diego scientist Jane Willenbring challenges the long-held belief that asbestos fibres cannot move through soil.

The findings have important implications for current remediation strategies aimed at capping asbestos-laden soils to prevent human exposure of the cancer-causing material.

Willenbring, along with University of Pennsylvania postdoctoral researcher Sanjay Mohanty, and colleagues tested the idea that once capped by soil, asbestos waste piles are locked in place.

Instead they found that dissolved organic matter contained within the soil sticks to the asbestos particles, creating a change of the electric charge on the outside of the particle that allows it to easily move through the soil.

"Asbestos gets coated with a very common substance that makes it easier to move," said Willenbring, an associate professor in the Geosciences Research Division at Scripps. "If you have water with organic matter next to the asbestos waste piles, such as a stream, you then have a pathway from the waste pile and possibly to human inhalation."

Asbestos comprises six naturally occurring minerals that are formed by thin fibres. Asbestos mining in the US began in the late 19th century and was widely used in a variety of products from insulation to car brake pads.

The US Environmental Protection Agency currently caps asbestos waste piles with soil to avoid human exposure to the toxic dust that causes a rare cancer called mesothelioma.

The National Institute of Environmental Health Sciences (NIEHS) Superfund Research Program funded the research.