"Something in the Air: When Hazardous Vapors Slip Indoors"

"The movement of vaporous underground contaminants into homes and buildings is attracting increased study — and scrutiny from health experts."

"When Jane Horton bought her dream 800-square-foot farmhouse in 1975, she thought little of the semiconductor manufacturing plant across the street. Even after the company’s buildings were demolished and a chain-link fence went up around the campus, she still had no knowledge of the toxic dangers lurking beneath her feet — let alone of the fact that they were invading her home.

It wasn’t until the early 2000s that Horton and other residents of Mountain View, California, heard about the underground plume of trichloroethylene, or TCE — a cancer-causing liquid used at the facility to clean silicon chips. Horton learned that vapors from the TCE were seeping up from the groundwater and soil into local buildings. When investigators tested the air inside her family’s house in 2004, they found concentrations of TCE exceeded a site-specific threshold set by the U.S. Environmental Protection Agency. And that was after approximately 75 percent of the contamination had already been cleaned up.

“We’d been over the plume the whole time,” says Horton, whose youngest son was still in elementary school when the vapors were discovered. “I can remember being so outraged that everything took so long. I’m wondering: Are my kids going to get cancer? Are my kids going to die? How am I going to be?” A venting system the EPA installed in her cellar now sucks toxic gases up from the soil, sending them through pipes and out a rooftop stack into the air, where they would be quickly diluted to acceptable levels. Periodic monitoring by the agency has since shown that the TCE levels at the house are safe."

Lynne Peeples reports for UnDark September 22, 2017.