Researchers at Texas Tech University say a toxic ingredient found in rocket fuel has made its way into breast milk.
The ingredient perchlorate was found in all samples of breast milk from 36 women in 17 states.
The study says the compound, on average, was 5 times greater in breast milk than cow's milk and 20 times higher than the safe limit set by the National Academy of Sciences.
Researchers believe the chemical enters women's bodies through foods they eat.
High levels of the compound are in the Colorado River which supplies irrigation to Southern California's cropland.