Although the toxicity values presented in these toxicity profiles were correct at the time they were produced, these values are subject to change. Users should always refer to the Toxicity Value Database for the currect toxicity values.
Lead occurs naturally as a sulfide in galena.
It is a soft, bluish-white, silvery gray, malleable metal with a melting point of 327.5C. Elemental lead reacts with hot boiling acids and is attacked by pure water. Lead is a natural element that is persistent in water and soil. Most of the lead in environmental media is of anthropogenic sources. The efficiency of lead absorption depends on the route of exposure, age, and nutritional status. The half-life of bone lead is more than 20 years.