Bismuth is essentially nontoxic in ordinary amounts, but prolonged exposure or excessive use may lead to toxicity. This could cause mental confusion, memory loss, incoordination, slurred speech, joint pain, or muscle twitching and spasm.

The human body contains about 3 mg. of bismuth. Many people take in 20-30 mcg. per day, most of it in water, a minimal amount in food, and some from airborne contamination. Most bismuth is eliminated in the feces and urine. Some drugs, particularly remedies for the stomach, such as Pepto-Bismol, contain bismuth.

Source: Elson M. Haas M.D. (Excerpted from Staying Healthy with Nutrition: The Complete Guide to Diet and Nutritional Medicine)