toxicity (to humans)

Elements toxic to humans include lithium, beryllium, oxygen (as ozone) fluorine, phosphorus, chlorine, potassium, chromium, vanadium, iron, arsenic, bromine, rubidium, cadmium, antimony, tellurium, iodine, cesium, mercury, thallium, lead, polonium, astatine and the actinides. The transactinides would be toxic due to radioactivity if for no other reason.