the long run, exposure to some of these chemicals may be just as deadly. These pollutants, including dioxins and furans, can be lethal in minute doses, and they do not remain in the air forever. When they settle, a few yards or hundreds of miles away, they can be absorbed into the groundwater and begin the slow process of moving up the food chain until they reach our dinner table. Many of these chemicals accumulate in the body and may be the cause of various cancers. Chemicals such as benzene, chlordane, xylene, toluene, lead, mercury, cadmium, selenium, arsenic, tetrachloroethylene, chlorophenols, dioxins, furans, and hundreds of others are present at detectable levels in human body tissue. There is not a person alive today who will not have some synthetic substance show up in the blood if it is looked for. These substances tend to collect in the fatty tissue of the body. Many are potent carcinogens (agents that cause cancer) and mutagens (agents that cause birth defects). They may be slowly ticking time bombs waiting 20, 30, or 40 years after entry to confront the body with a cancer of some type. They may be silent cofactors in causing disease, along with well-known cancer-causing substances like tobacco, asbestos, and others. Their effects may not even show up until we have children with birth defects such as spina bifida, cleft palate, Down's syndrome, or heart abnormalities. And they can increase the rate of miscarriage and stillbirth. TCDD, a form of dioxin, is considered by many experts to be the most toxic chemical ever created. ] ]