It is not clear if these effects would happen in people at similar levels of exposure. Smaller amounts over several weeks or months caused liver, stomach, and thyroid gland injuries, anemia, acne, and reduced the ability to have offspring. Similar effects occurred in different laboratory animals. This is based on animal studies. Studies in workers do not provide enough information to know with any certainty if PCBs cause cancer in humans.
Tests are available for PCBs in blood, body fat, and breast milk.
Blood tests are the best method for detecting recent exposures to large amounts. These tests are not routinely performed at your doctor's office. High levels in your body fluids indicate exposure to high levels of PCBs. These tests can't determine the exact amount or type of PCBs, how long you were exposed, or if you will develop harmful health effects. Most people have small but measurable amounts of PCBs in their blood, fat, and breast milk.