The chemicals find their way into the food chain and into our bodies.
Now a study in the Journal of the American Medical Association suggests elevated levels of PFC chemicals may weaken the effectiveness of childhood vaccines.
According to the research, mothers with elevated PFC levels had children whose diphtheria vaccines were 39 percent less effective.
Children who also tested for high levels of the chemical were also at risk of a deficient immune response after tetanus and diphtheria vaccines.
