The weight of the evidence strongly says PCBs are a risk to human health. It's not just cancer, as if that were that not enough. Multiple studies from the U.S. and from Europe reveal PCBs' impacts on the ways that the brain and the immune system develop. Kids exposed to even modest levels of PCBs in the womb can have reduced intelligence and are not as able to resist disease as children with less exposure. Animal experiments support this work by showing that animals exposed in the womb reliably suffer from PCB exposure.
Humans are more complicated, making scientific certainty more difficult.
But together, combined with corroborative work on animals where possible, the weight of the evidence is enough to convince independent, reasonable scientists that PCBs represent a clear and present danger to human health. We know at least three Republican leaders who would agree. John Peterson Myers is director of the W. Alton Jones Foundation in Charlottesville, Virginia, and co-author of Our Stolen Future, a book about contamination threats to children's health. OurStolenFuture.org for scientific information about PCBs and other contaminants. Lisa A. Guide was Assistant Secretary of the Interior under the Clinton Administration, and is now executive director of Talking Stick Strategies.