Germanium: Environmental Pollution and Health Effects

Germanium is a metalloid element. Inorganic germanium is mined and widely used as a semiconductor in the electronics industry, whereas organic germanium is chemically synthesized or extracted from the germanium-containing plants. Even though no physiological function or deficiency syndromes of germanium have been documented in humans, germanium is reported to be capable of inducing erythropoietic, antimicrobial, antiviral, antimutagenic, antitumor, and immunomodulating effects. Therefore, the use of dietary supplements containing inorganic or organic germanium to promote health or cure diseases became popular in the 1970s. Thereafter, numerous reports showed that such supplements present a potential hazard to humans. In fact, unless taking a great quantity of supplements, daily intake of germanium from food in adults ranges only from 0.367 to 1.5 mg, which is not toxic to humans. Exposure to germanium may also occur through inhalation in certain industrial environments. GeCl4 vapors and GeH4 gas can strongly irritate the eyes, the skin, and the respiratory tract. In particular, GeH4 is highly toxic and can cause hemolysis and death. In addition, people may encounter germanium exposure in their living environments. It has been noted recently that wastewater carrying toxic germanium contaminants can damage the ecosystem and human health.