text: Lead has no known biological role, and is in fact highly toxic, but some microbes are able to survive in lead-contaminated environments. Some plants, such as cucumbers contain up to tens of parts per million of lead. There are 120 milligrams of lead in a typical 70-kilogram human.
  Flerovium has no biological role and instead is found and made only in particle accelerators.
  Toxicity
  Elemental carbon is not generally toxic, but many of its compounds are, such as carbon monoxide and hydrogen cyanide. However, carbon dust can be dangerous because it lodges in the lungs in a manner similar to asbestos.
  Silicon minerals are not typically poisonous. However, silicon dioxide dust, such as that emitted by volcanoes can cause adverse health effects if it enters the lungs.
  Germanium can interfere with such enzymes as lactate and alcohol dehydrogenase. Organic germanium compounds are more toxic than inorganic germanium compounds. Germanium has a low degree of oral toxicity in animals. Severe germanium poisoning can cause death by respiratory paralysis.
  Some tin compounds are toxic to ingest, but most inorganic compounds of tin are considered nontoxic. Organic tin compounds, such as trimethyl tin and triethyl tin are highly toxic, and can disrupt metabolic processes inside cells.
  Lead and its compounds, such as lead acetates are highly toxic. Lead poisoning can cause headaches, stomach pain, constipation, and gout.
  Flerovium is too radioactive to test if its toxic or not although its high radioactivity alone would be toxic.