Just how worried is Cindy Crawford about toxic chemicals in schools?
So much so that she's been keeping her two teenaged kids home, after elevated levels of a cancer-causing chemical often found in older buildings were detected at the Malibu schools they attend.
Crawford has two children with husband Rande Gerber, son Presley Walker, 15, and daughter Kaia Jordan, 13.
"I don't feel 100 percent safe," the supermodel, 48, tells NBC special correspondent Maria Shriver bluntly during a segment that aired Tuesday on Today. "I look 10 years down the line. What if my kid, God forbid, had a problem? How could I live with myself, if I knew that it was a possibility, and I still sent them to school there?"
It all started when Malibu teachers became concerned about their health, and tests at the school detected high levels of PCBs -- toxic chemicals often used in the window caulking of older schools -- in four of the 10 random classrooms they tested.
Over time, PCBs can cause cancer and damage to the immune and reproductive systems.
In 1976, Congress banned them from use.
Though the Malibu school district is planning to remove the caulking where the level of PCBs came back over the federal limit, and do periodic monitoring of air and dust for PCBs in every classroom, for Crawford, it's not enough.
"The problem is for me, they haven't tested the source," she says. "... Unless they're testing every day, how do I know it's safe for my kid?"
Check out the video above to see a clearly passionate Crawford at a rally speaking about the issue, which has become a national controversy for schools.