When Oakland resident Katrina Friedman, 31, agreed to join the study, she assumed that her healthy diet, yoga and a clean job at Hot Studio, a small San Francisco design firm, was producing chemical-free milk for her baby daughter, Ruby.

But Friedman had PBDE levels in her milk at 79 parts per billion, higher than the number that triggered a ban of the flame retardants in Europe.

“I love my child more than anything. I want to protect her from broken glass, bullies at school and invisible poisons like this one. But I’m powerless. These chemicals aren’t banned in the United States, and we’re just continuing to add them in the environment,” Friedman said.