Michelle Hammond and Jeremiah Holland were intrigued when a friend at the Oakland Tribune asked them and their two young children to take part in a cutting-edge study to measure the industrial chemicals in their bodies. Rowan

"In the beginning, I wasn't worried at all; I was fascinated," Hammond, 37, recalled.

But that fascination soon changed to fear, as tests revealed that their children -- Rowan, then 18 months, and Mikaela, then 5 -- had chemical exposure levels up to seven times those of their parents.

"[Rowan's] been on this planet for 18 months, and he's loaded with a chemical I've never heard of," Holland, 37, said. "He had two to three times the level of flame retardants in his body that's been known to cause thyroid dysfunction in lab rats."