Cindy Crawford's two children missed their first day of school at Malibu High School due to elevated levels of PCB, the model confirmed.

PCB, a chemical often found in the window caulking of older buildings, was outlawed by Congress in 1976 and has been found over time to cause cancer, immune system damage and negatively impact brain development.

Cindy appeared on the Today Show Tuesday with special correspondent Maria Shriver to talk about her concerns.

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Cindy's two children with hubby Rande Gerber

“I don’t feel 100 percent safe,” she said of sending kids Presley and Kaia to school. “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…"

Although the 48-year-old offered to pay out of pocket for window caulking tests at Malibu High School, the EPA (Environmental Protection Agency) ruled the immediate problem has been handled through air testing.

“I am very frustrated and very disappointed,” Cindy shared. “The problem is that they haven’t tested the source. Unless they’re testing every day, how do I know it’s safe for my kid?”

The brunette beauty, who earned a scholarship to study chemical engineering at Northwestern University in the '80s, said PCB is not just an issue in Malibu. "This is really an issue in a lot of older schools," she said on the morning program. "I just think the laws need to be changed.”