Bismuth exists in nature in the form of free metals and minerals. The metal Bismuth is obtained by calcination of minerals into Bismuth trioxide, followed by co-thermal reduction with carbon, and high-purity Bismuth can be obtained by fire refining and electrolytic refining.
Bismuth is a micro-toxic class. Most compounds, especially salt-based salts, are difficult to absorb in the digestive tract. Do not dissolve in water, only slightly soluble in tissue fluid. Can not be absorbed through intact skin and mucous membranes. Bismuth is absorbed throughout the body, with the most kidneys and the liver. Most of the Bismuth stored in the body is excreted in the urine for weeks or even months.
Bismuth's metabolism in the body is similar to lead. In the case of acidosis, the tissue releases the accumulated Bismuth. Bismuth and lead can interact with each other. In vivo, Bismuth compounds form a sulfurized Bismuth that is less soluble in water and dilute acids, precipitates in tissues or is plugged into capillaries, causing local ulcers and even necrosis. Under the action of bacteria in the intestine, Bismuth nitrate can be reduced to nitrous bismuthum, which causes methemoglobinemia after absorption. In severe chronic poisoning, due to the presence of Bismuth in the kidney, severe nephritis may occur, of which the damage of the renal tubular epithelial cells is the heaviest and the liver may be involved. The “Bismuth line” may appear in patients with chronic poisoning who have been repeatedly orally or by other means.
No occupational poisoning caused by inhalation of Bismuth and its compounds was observed. Chronic poisoning is mainly caused by drugs containing soluble Bismuth salts. Intravenous or intramuscular injection of soluble Bismuth salts has been reported to have caused death.
Those with skin damage should avoid direct contact with soluble Bismuth salts. Sodium dimercaptopropane sulfonate can be used as an antidote.