How do toxic substances enter the body?
Common areas where toxic substances enter the body are the skin, eyes, nose, throat, and lungs. Usually when a chemical enters the body it either lodges in the body—as asbestos does in the lungs—or travels through the bloodstream to internal organs. The organs most commonly affected are the liver, kidneys, heart, and brain; the nervous system and reproductive system may also be affected.

How do toxic substances harm the body?
Harm from toxic substances manifests itself in many ways. Possible scenarios may involve skin problems (e.g. dermatitis, rash, and blistering) to impaired mental development (a possible outcome of lead poising in children), to organ failure, disease, and sometimes death.

Harm is not limited to exposed individuals; the offspring from such people may also suffer. For example, a pregnant woman exposed to chemicals, in the workplace, places her unborn child at risk. Birth defects, autism, and attention deficit hyperactivity disorder are not uncommon in the children of exposed workers.